The Design Mistake That Turns a 210E Authorization Into a TCEQ Violation

Why is approval the start of the obligation, not the end?

Because TCEQ approved specific numbers, and every one has to hold in the field. Under 30 TAC §210.55(b), a Level II application states the end use, the waste source, the reuse site, the primary disposal method used instead of reuse, and the volume and frequency of application.

A 210E authorization is approval of that plan. TCEQ's reclaimed water guidance says the agency must approve any change to a use it has already approved. So a field change to the irrigated area, the storage or the flow is a compliance question, not a construction detail.

The rules below are the Subchapter E rules for industrial reclaimed water. If any domestic wastewater is in the stream, it is commingled water under §210.52(3), and §210.56(a)(1) also puts it under the domestic reclaimed water rules in Subchapters A to C. Confirm the path with TCEQ early. This post is about the design and construction side. Our post on 210E authorization compliance covers sampling, records and the yearly check.

Why does wet weather expose undersized storage?

Because the rule stops irrigation exactly when the plant keeps producing. Under 30 TAC §210.56(f)(3), no industrial reclaimed water may be land applied when the ground is frozen or saturated, or during rainfall.

Storage has to carry the water through those days. Section 210.56(g) requires at least two feet of freeboard in retention, holding and transfer ponds, and says ponds shall not be used for disposal. A pond sized for an average month runs out of room in a wet stretch.

That is when the primary disposal method in the application earns its place. If that route is not built, not contracted or not big enough, the overflow, ponding or runoff that follows does not match the approved plan. The next section covers the water balance that sizes both.

How should the reuse area be sized?

From a monthly water balance, not an annual average. Section 210.56(f)(1) sends industrial reuse irrigation to the general irrigation rules in 30 TAC §210.24. Those rules ask for documented irrigation demand based on vegetation and area.

The water balance uses average monthly precipitation from past records and a monthly crop consumptive use, with a leaching allowance where dissolved solids could build up in the soil (§210.24(d)(1)). The design must also prevent overflow, avoid ponding and provide tailwater controls so reclaimed water does not leave the site.

An annual average hides the winter months when demand drops and rain falls. Those months set the storage. They also show whether the area was ever big enough for the stated volume.

What happens when construction clips the irrigation area?

The approved volume no longer fits the land. An easement, a road realignment or a later building can take part of the field. On the drawings it looks like a small grading change. Against the authorization, it is a smaller use site taking the same volume.

Catch it before the change is built, and it is an amendment request to TCEQ. Catch it after a wet season, and it is a violation finding with a redesign attached. That is why reuse area and design flow belong in the same calculation from the start. Our 210E work includes a reuse authorization for a mixed-use development in San Marcos, Hays County.

Which setbacks get lost during construction?

Well buffers, spray limits and the floodway line. Each is a fixed rule the site plan had to prove, and each can be undone in the field.

• Under §210.56(f)(4), industrial reclaimed water may not be applied within 250 feet of a private water well or 500 feet of a public water supply well.
• Under §210.24(d)(5), spray may not reach privately owned land outside the irrigation area, or public drinking fountains.
• Under 30 TAC §210.23(a), storage facilities stay out of the floodway, and initial holding ponds are lined unless the water is kept in leak-proof tanks.

A sprinkler head moved toward a lot line or a new well drilled near the field can each break a buffer that was clean on the approved plan.

What do signs, pipe color and separation require?

Proof that nobody mistakes reclaimed water for drinking water. 30 TAC §210.25 sets the physical controls:

• purple hose bibs and faucets that a standard hose cannot connect to, in locked vaults or special-tool boxes;
• signs at least 8 by 8 inches in English and Spanish, such as "Reclaimed Water, Do Not Drink," or a storage area secured from the public;
• at least nine feet of horizontal separation from potable piping, or the Chapter 290 line separation rules where that cannot be met;
• purple pipe, purple paint, purple tape or purple bagging, with exposed pipe stenciled "NON-POTABLE WATER."

Backflow protection on the potable side sits in the drinking water rules, 30 TAC §290.44(h). These items are cheap during construction and costly after an inspector finds them missing.

How does TCEQ respond when the built system drifts?

With suspension, and possibly a permit requirement. Under 30 TAC §210.59(b), the executive director may suspend an authorization when the quantity used, the type of waste or the type of operation does not comply with Chapter 210. A suspension notice may require use to stop and may require an individual permit.

TCEQ may also deny or suspend for adverse impact or close proximity to a park, school, spring, aquifer or water supply well (§210.59(a)). Before approving any Level II authorization, it weighs the compliance history of the producer, provider and user (§210.59(c)).

What should you check during construction?

Run this against the approved plan before startup, and again after any field change. Each "no" goes to your engineer, and possibly to TCEQ, before the system runs.

1. Is the irrigated area the one in the application, with no part lost to an easement, road or building?
2. Does the storage volume carry the wettest months in the water balance, with two feet of freeboard?
3. Is the primary disposal method built or contracted, and sized for the days irrigation must stop?
4. Are the well buffers and spray limits intact on the as-built layout?
5. Are the pond liners certified, and is storage outside the floodway?
6. Are purple pipe, labeling, signs, separation and backflow protection installed as designed?
7. Can the operator reach every sampling point and storage control?

A note on limits: this is general education on 30 TAC Chapters 210 and 290 as published in October 2026. Your authorization may add conditions, and TCEQ decides how any change is handled.

Frequently asked questions

What is the most common cause of a 210E violation?

Storage and reuse area sized to average conditions. The rule stops land application on saturated or frozen ground and during rainfall, so wet months set the storage, and a pond may not be used for disposal.

Can I irrigate with reclaimed water during rain?

No. Section 210.56(f)(3) bars land application of industrial reclaimed water when the ground is frozen or saturated, or during rainfall events.

I'm a developer in Hays County, and our contractor wants to shift part of the 210E irrigation field to make room for a utility easement. Is that a field change or a TCEQ issue?

Treat it as a TCEQ issue. TCEQ must approve changes to an approved use, and the use site is part of your application. Have your engineer rerun the water balance and ask TCEQ about an amendment before the work is built.

What happens if a 210E system no longer matches its authorization?

The executive director may suspend it under §210.59(b), may require use to stop, and may require an individual permit.

I'm a Texas civil engineer reviewing as-builts for a reuse system before startup. Which separation rules should I check first?

Check the well buffers in §210.56(f)(4), the spray limits in §210.24(d)(5), and the nine-foot separation from potable lines in §210.25(c). Then confirm the backflow protection required under §290.44(h).

Related resources

• What TCEQ's 30 TAC Chapter 210 Actually Requires for Effluent Quality Under a 210E Authorization
• 210E vs. TPDES Discharge Permit: A Side-by-Side Comparison for Developers
• Getting a Discharge Permit as a Backup After Your 210E Is Operational
• 210E Public Notice Requirements: What TCEQ Actually Requires Before Approval

Worried your 210E system might drift from its authorization?

We check the built system against the approved plan, from storage and reuse area to buffers and signs, before a wet season or an inspection finds the gap.

We specialize in:

• 210E and Chapter 210 reuse authorizations
• Reuse area and storage design
• Wastewater treatment and reuse system design
• TCEQ wastewater permitting
• Construction administration

Modern Engineering Solutions, McKinney, Texas. Contact: (214) 833-6748 or mod-eng.com